The overall objective of the research is to biochemically characterize the allogeneic cytotoxic T-cell receptor. H-2 antigens, which have already been purified, will be used in binding studies to cloned T-cell lines. The receptors will then be isolated by monoclonal antibodies to the bound antigens. The first component of the project involved the establishment of cytotoxic T-cell lines of the correct specificity. Cloned T-cell lines are required in order to obtain sufficient homogeneous preparations of the receptors for the study. Although cell lines of the correct specificity have been derived, none of these have proven to be stable in long-term culture. If no stable cell lines are established in this laboratory by the end of the first year of the research, we plan to obtain these lines from other laboratories with established cell lines in order to be able to proceed with the experiments. Supplementary to the original grant proposal, several T-cell reactive monoclonal antibodies have been established and are being characterized. (CS)